Those false beliefs (5)
I believe the answer is:
ethos
'beliefs' is the definition.
(I've seen this before)
'those false' is the wordplay.
'false' indicates anagramming the letters.
'those' anagrammed gives 'ETHOS'.
(Other definitions for ethos that I've seen before include "Character of a community or age" , "Distinctive spirit of an institution" , "Distinctive attitudes of a people" , "Distinctive spirit - character" , "Distinctive group attitudes" .)